Chiccoli C, Pasini P, Skacej G, Zannoni C, Zumer S
INFN, Sezione di Bologna, Via Irnerio 46, I-40126 Bologna, Italy.
Phys Rev E Stat Nonlin Soft Matter Phys. 2002 May;65(5 Pt 1):051703. doi: 10.1103/PhysRevE.65.051703. Epub 2002 Apr 29.
In this Monte Carlo study we investigate molecular ordering in a nematogenic liquid with dispersed polymer networks. The polymer network fibers are assumed to have rough surface morphology resulting in a partial randomness in anchoring conditions, while the fiber direction is assumed to be well defined. In particular, we focus on the loss of long-range aligning capability of the network when the degree of disorder in anchoring is increased. This process is monitored by calculating relevant order parameters and the corresponding 2H nuclear magnetic resonance spectra, showing that the aligning ability of the network is lost only for completely disordering anchoring conditions. Moreover, above the nematic-isotropic transition temperature surface-induced paranematic order is detected. In addition, for perfectly smooth fiber surfaces with homeotropic anchoring conditions topological line defects can be observed.
在这项蒙特卡罗研究中,我们研究了具有分散聚合物网络的向列型液体中的分子有序性。假设聚合物网络纤维具有粗糙的表面形态,导致锚定条件存在部分随机性,而纤维方向被认为是明确的。特别地,当锚定无序度增加时,我们关注网络远程排列能力的丧失。通过计算相关序参量和相应的2H核磁共振谱来监测这一过程,结果表明只有在完全无序的锚定条件下网络的排列能力才会丧失。此外,在向列相-各向同性转变温度以上,检测到表面诱导的顺排相序。另外,对于具有垂直锚定条件的完全光滑纤维表面,可以观察到拓扑线缺陷。